Oscillator



May 20, l952 A. E. BROUGHTON 2,597,443

oscILLAToR Filed Aug. 6, 1949 5 Sheets-Sheet l w w i 1a e 4V .uw www w\m\ mm m kf@ el.. www w zw www .1 QN f Z m 5w IrI r l; ww mw um i 1 AH\N ,i NN QM/. m m QN N R .im NN Ix 7 1M .7 "l u l www +Mw QN w M N @www u N Mmmm Q kw 4 m QN SN N MWk Q Q X *WJ Q .RN m 4 RMN www iw. NN ,B w

May 20, 1952 A. E. BROUGHTON 2,597,443

oscILLAToR Filed Aug. 6, 1949 3 Sheetrs-Sheet 2 ffy Patented May 20, 1952 UNITED STATES PATENT OFFICE Arthur E. Broughton, Glens Falls, Y. Application August 6, 1949, Serial No. 108,908

6 Claims. 1

This invention relates to reciprocating fluid motors.

In the manufacture of paper it is desirable to reciprocate various partsl of the paper making machine such as showers, doctors, and other parts. In many other arts it is desirable to reciprocate certain parts. Fluid motors have been extensively used for this purpose operated either hydraulically or pneumatically, particularly when electric motors or other types of motors are undesirable for use as, for example, in the paper making field where due to the moisture always present around paper making machine electric motors` are uncertain. often dangerous, and undesirable.

It is one ofthe objects of the present invention to provide ai novel' and improved reciprocating uid motor, the strokeof which canl be' easily varied in length-and including control mechanism whichwill slow down the movement of the reciprocating part near the end of the stroke in each direction so that the reciprocating part will not be brought to an abrupt stop at theren'd of one stroke immediately preceding its stroke in the opposite direction.

A further object is to provide suoli a recipro-V cating fluid motor including'y a cylinder andv a double acting piston working. in the cylinder andV a control mechanism adapted alternately to supply and exhaust iiuid at the opposite sides of the piston inv the cylinder,n the control mechanism being so constructed that as the piston approaches the end of its stroke in either direction the movement of the piston is slowed down to accomplish the change in` direction smoothly and gradually.

A further object is to provide such a recipro-V cating fluid motor as referred toin the last paragraph wherein the control mechanism includes a. main valve and a retarding. valve actuator for actuating the main valve, the actuator being con-- nected to the piston through a limited play linkage and the actuator having a limited' movement relative to the main Valve before actuating the main valve.

A still more detailed object is to provide such acontrol mechanism as in the" last paragraph referred to wherein the actuator and the main activating iluid.

The objects and advantages of the invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the dillerent views, and in which valve are cushioned by the movement of both the closes the left or inner vFigLgl is a longitudinal sectional view through f (Cl. 12h-164) as they will appear just after the piston has completed its stroke toward the right end of the cylinder and after the parts have been shifted to the right and as the piston starts' itsv stroke toward the left end of the cylinder;

Fig.3 is a view in enlarged sc'al'e through portions of the control mechanism showing the parts as they will appear during the first stages of the shifting of the parts from the position shown inv Fig. 1 to the Fig. 4 is a view in horizontal section takensubstantially on the line 4-4- of Fig. 3 and'Fig. 5 as indicated by the arrows:

Fig. 5 is a vertical section taken approximately on the line 5 5 of Fig. 1 as indicated by the arrows;

Fig. 6 is a vertical section taken approximately on the line li64 of Fig. 4 as indicated by the arrows;

Fig. 7 is a View in side elevation of the sleeve of the control mechanism, a portion of the same being brokenaway;

Fig. 8 is a view in enlarged scale looking towardthe left end of the said sleeve as seen in on the lines 9f9, IfJ-v-I'll, of Fig. 7 as indicated by the side'elevation of the main Fig. 15 is aview in side elevation of the retard`Y Y ing valve actuator ;v and Fig. 16 is a vertical section taken on the line" IG-IG of Fig. 15 as indicated by the arrows.

Inv accordance with the invention andas il1'ustrated in the embodiment shown,Y there is provided a hollow cylinder I l having attached to its left or inner end a flange I8 which is bolted or otherwise secured to' a arige of a head I9 which end ofy the cylinder Hf. The right orV outer end secured to a hollow p istonrod 22g-this piston positionv shownv in Fig. 2

and 12l are Vertical sections of the cylinder has at-l tached theretoI a tail castingyZU which closes thel rod in turn projecting through the tail casting 20 and being packed against loss of fluid as it reciprocates back and forth in the tail casting 20 by a packing gland 23. The head I9 has a cylindrical chamber 24 formed therein, this chamber being axially aligned with the piston 2| and piston rod 22. The said chamber 24 runs from the outer end of the head I9 to the inner end thereof and a plug 25 screwed into the outer end portion of the head |9 closes the outer end of the chamber 24, while the inner end of the chamber is closed by another plug 26 screwed into an enlarged tapped portion of the chamber, this plug 26 having a central apertured cylindrical bearing 21 formed preferably of nylon or other suitable bearing material through which extends a pitman rod 28. The inner or left end of the piston rod 22 has screwed thereto a front stop nut 29 through which the pitman rod 28 extends, and the rear end portion of the hollow piston rod 22 is closed by a plug 30, the inner end of which also acts as a stop. The pitman rod 28 carries within the hollow piston 22 a pitman rod stop nut 3|, and

it will be seen that the relative movement of the rod 28 to the piston rod 22 is limited in one direction through engagement between the inner end of the stop nut 3| carried by the pitman rod and the stop nut 29 carried by the piston rod 22 and that similarly relative movement between the pitman rod 28 and the piston rod 22 is limited in the opposite direction by engagement between the outer end of the stop nut 3| carried by the pitman rod and the inner end of the plug 30. The piston rod 22 and, hence, the double acting piston 2| thus has connection to the part to which the left end of the pitman rod 28 is connected through a limited play linkage. The stroke l of the piston 2| can be readily varied as will be presently seen through variance in the length of the plug 30 or through variance in the length of the stop nut 3| and in this manner it is readily possible to vary the stroke of reciprocation of the particular mechanism which will be actuated-by the reciprocating fluid motor of the present invention. It, of course, will be` appreciated that the outer or right end of piston rod 22 in practice lwill be connected to whatever member-it is desired'to reciprocate.

Received within the chamber '24 of the head I9 and held-in place therein against rotation by the two nuts 25 and 26 is a main valve sleeve 32. This sleeve 32 centrally of the two ends thereof has a plurality of fluid supply ports 32a, which are freely in communication with a circular groove 33 cut in the head I9 to annularly surround the central portion of the sleeve 32. The groove 33 in turn is in communication with a fluid intake passage 34 communicating with the upper head end of a strainer chamber 35. The strainer chamber is formed by a strainer head 36 integral with the head I9 in the illustrated embodiment, and attached to this strainer head 36 is a strainer cylinder or body 31 having attached at its lower end a flange 38. The centralA portion of the strainer head 36 is bossed and 'tapped to form a fluid inlet 39 to which such a fluid as water or air may be supplied under pressure. motor is to be operated hydraulically, a pipe connection will be made from the ordinary water supply main to the fluid inlet 39, the water pressure employed being that normally used in city water supply systems. If the fluid motor is Vto be pneumatically operated, the fluid inlet 39 will be connected to a source of air or other gas supply under comparatively light pressure.- A Y Figs. l to 4 and in Mounted in the bossed aperture forming the fluid inlet 39 is a strainer tube 40 and this tube at its lower end, as best illustrated in Fig. 5, has received thereover a strainer cover 4 I. The lower end of the tube is closed by a plug 42, and a nut 43 is threaded on to the lower end of the tube 40 and forces the strainer cover 4| tightly upwardly against a gasket 44 located between the cover 4I andthe flange 38. A lock pin 43a running through the nut 43, the tube 40 and the plug 42 holds the parts assembled in place. Within the lcylindrical chamber formed by the strainer head 3S, cylinder 31 and cover 4I the tube 40 is provided with apertures 4Ia permitting the flow of fluid from the tube. A strainer basket 45 carries at its lower and open end a flange 45a which bears against the flange 38 and the basket 45 projects upwardly Ato encompass the tube 40, the tube being equipped with a nut 46 near its upper end against which the closed but apertured end portion of the basket 45 bears. A coil spring 41 bearing at its lower end against u the strainer cover 4| and at its other end against the disc closing the upper end of the basketv 45 retains the strainer basket in position. While any other suitable strainer arrangement may be provided for straining the fluid as it runs from the fluid inlet 39 to the passage 34 and thence groove 33 and'to the inlet portions sleeve 32, the construction shown serves the purpose well.

Now referring back to the main valve sleeve 32, this valve sleeve, as can perhaps best be seen in Fig. '1 and as also seen in Figs.- 1, 2, 3, 10, and 12, is equipped with two fluid transmission ports, one of which will be numbered 32h land designated the first other of which is numbered 32o and willv be designated the second fluid transmission port. These f two ports 32h and 32e are located laterally of the fluid intake ports 32a, one at either side of these ports, considering the sleeve 32 as it appears in Fig. 'I of the drawings. The spacing of the ports 32h and 32e toward the two ends of the sleeve 32 from the intake ports 32a is rather close, however. The first iluid transmission port 32D communicates with a fluid transmission passage 48 which runs through the head I9 and communicates with the cylinder I1 at the left or near side of the double acting piston 2|. The second fluid transmission port 32o communicates with a'second fluid transmission passage 49 formed in the head I9 and the passage 49 com- 1 first fluid transmission branch ofV a branched exhaust passage 52 formed? municates with a tube 50 tending between the head I9 and the tail casting 20 and forming a continuation of the second fluid transmission passage of this passage is made by a passage 5I formed in the tail casting 20, the passage 5I communicating with the cylinder the side with which the passage 49 communicates. The sleeve 32 spaced toward the respective acting piston 2| from ends of the sleeve from the first iluid transmis- 32h and the second fluid transmission. port 32o is equipped with two exhaust ports 32d and 32e, respectively, which are best shown 'in-1 sion port Figs. 4, 7, and 9 of the drawings. These ports are located approximately degrees from the ports 32h and 32o on and-both ports 32d and 32e communicate with a in the head I9 and communicating with an exhaust pipe 53 equipped with a, regulating valve 54,

32a in the main valve.

fluid transmission port, and the;

mounted in .and ex- 49. A further continuation.

I1 at the far or right side of the same and at the opposite side of the double the surface of the sleeve 32,l

the exhaust pipe 53 l'running to a suitable point as to a drain'or the like whereinthe fluid'passing through'the same may be discharged,

'The'left end portion of the sleeve 32 is provided with a short longitudinal groove 32f cut in its inner wall asbest shown in Figs. 4, 7, and 8 for apurpose presently'to appear.

Slidablyfitting within the main valve sleeve 32 for reciprocating movement relativel theretov betweenthe-plugs 25'and l26 is a vmain valve 55. This :valve has a tubular body portion equipped with four .outwardly projecting grooved lands .which are spaced one from another .longitudinally of the valve and `,which are designatedrespect-ively55a, 55b,.55c, and 55d. Due tothe fact that the lands project radially outwardly from the body of the valve greater distances than other portions Vof the exterior surfaces of the'valve, three grooves 55e, :551 and 55g., respectively, are formed at the exterior of the main vvalve 55. The main valve 55, as is best seen in Figs. 1, 2, 3, 13, and 14, is also provided with a pair of opposed ports 55h running from the central groove55f i-n'to the interior of the valve. The rarrangement of the grooves 55e, 55j, and 55g and of the lands $511,551), 55o, and 55d is such relative to the various ports 32a, B2b, 32e, 32d, and 32e that when the-main 'valve 55 is slid to the extreme left hand position as viewed in Fig. 1, Fig. 3, and Fig. 4, the groove '55j willv span the space between the fluid supply ports 32a and the iirst fluid transmission port B2b, while the groove 55g will span the space between the second fluid transmission port 32o andthe `fluidexhaust port 32e. At this time also the groove 55e will be in communication with the exhaust passage 52 through the exhaust port 32d. The land 55C vwhen the main valve is inthis position will prevent communication between the supply ports 32a and the groove 55o', while the land 55h will -prevent communication between the supply ports 32a and the groove 55e. The groove 32j is slightly longer than the land 55a, and, hence, communication is possible between the-left end-portion of the chamber 2li and the groove 55e. Now, if the main valve -55 is slid to the extreme right hand position as best seen in Fig. 2, the groove 55f will bridge the space between thexsupply ports 32a and the second uid transmission port 32o, while the groove 55e will lspan vthe space between the iirst fluid transmissionport V32h and the exhaust port 32d. At this time ythe ,groove 55g will be in communication with the exhaust port 32e.

ASlidably received within the body of the main Ya1ve-55 is a valve actuator 56, sometimeshereafter called a retarding valve actuator because of its function. This actuator includes aftubular body provided with a central cross web or partition'a, and three grooved lands 55h, 55o, and 56d are formed in longitudinally spaced relation on :the exterior of the said body, thereby 'formingza'pair of grooves 56e and 55j between the respectiveadjacent lands. The actuator 56`is providedwith a pluralityof ports 56g and 56h. The ports 516g afford communication between the groove 56e and the interior of the Iactuator at the left/.of the partition 56a, while the .ports 55h afford'communication between the groove 56j and the interior of the actuator to the right of the partition 56a.

Longitudinal movement of the actuator 56 relative gto the main valve 55 is possible, this movement being limited to theleft as viewed in Figs. 1,.-2., 3.,and4 ofthe drawings by a split spring stop ring 51 mounted inarg1-coveformedadiacentthe left end of zthe `rniainV valvef.-55.; at the: inter-largeur* face the'reof and .being vlimitedto :the `right as viewed in these same views of thev drawings VV.by another split spring stop -ringr receivedwwithin a .groove .near the right end of .themain .val-ve 55 at the interior vsur-face thereof. `The pitman rod :28-projects intothe right end portiongofthe valve actuator 5E and'cairries at .its left-endwithin .this portion of the vactuator 'a stop nut-Silzlwhich at times may engage with the lright-side--of` 'the partition 56a fand at other times 'may engagewith a :split spring stopring-:SD mounted within .a groove formed :adjacent theright end voff-'the VVactuator 5t .at .the interior surfacevthereof. lThe nut .59.fits vloosely within .the right hand portion of `the actuator'55, and itwill be seenfthat the pitman rrod 23 which carriesthe stop nut'59 may have a limited reciprocating 2 movement relative tothe valve actuator 561before-either the left hand surface ofthe nut engages' the partition-56a or before the `right handvsurface of the stop nut 59 engages the stop ring 50.

Mounted for sliding movement in the plug-25 closing the left end of thecylindrical chamberid is a push key El which has an enlarged-headY at its inner end and which is aligned tolengagey 'at times with the left end of the-mainvaive55.

While the details of the doubleacting 'piston 2i working inthe cylinder can be considerablyfvaried, in the illustrated embodimentthis piston includes a central Washer "Zia mounted on the piston rod 2-2, a pair of oppositely cupped leathers 21o and 2ic, one at either side ofthe washer 2m, a Vpairof washers'ld andle'received within the cups of the leathers, and -apair of nuts 2U and Zlg screwed on to the piston rod 22 and holding the other parts of thepistonlassembled together.

The details of the f packing gland 23 maybe varied, butin the illustrated form this-packing gland includes a pair of'packing washers 23a, a shaft packing 23h of fibrous material between these two washers, a coil spring 23C bearing against the cuter washer 23, and a gland nut 23d-receiving the-'spring and bearing against the outer end'portion ofthe spring.

Operation Let us assume that the various parts -are in the position shown in Fig. 1 and that water is being supplied under pressure from 'the `fluid inlet 39 through the strainer and passage 34, groove-33 and iiuid supply ports 32a of the sleeve to the groove '55j of the main valve. -At 'this time the piston 2l is in its extreme left hand position in the cylinder yIl, the 'pitman rod 528 is in its extreme left 4hand position, `the nut-59 attached to Vthe pitman rod bears against the partition 56a, of the valve actuator and -both the main valve 55 and the actuatorl56 are'inctheir extreme left hand positions. The watersupplied through the iiuid `supply ports 32a -to thegroove 55j travels through .the `rlrst Atransmission port SZb-'andrst iiuidtransmission passage :481to the left `hand portion of the cylinder 1H, thereby causing the piston 2| `to travel to the :right v'as indicated by the arrow adjacent thereto in'Figl.

As the'piston 2| moves to the `right vthe water within the cylinder I-l at the right of vthepiston will be forced Yby the leather cup .2|c through the second iiuid'transmission passage formed-by passage 5I, tube 50 andpassage 49 and Ythrough the second fluid transmission port32c .into ithe groove g of the vmain valve f55from `whence it -itravels through the yexhaust kvport 3 2e. .exhaust passage 52 and exhaust pipe 53. The setting of the valve 54 which regulates the opening leading to the exhaust pipe 53 will regulate the rapidity with which Water may be exhausted from the cylinder |1, thereby regulating the speed of movement of the piston 2| dependent, of course, on the pressure of the supply fluid.

The valve 55, actuator 56 and the pitman rod 28 will remain in their left hand position until the water pressure behind the cupped leather 2lb oi the piston has forced the piston to the right to such a point that the stop nut 29 carried by the piston rod 22 engages the stop nut 3| carried by the pitman rod 28. As further travel of the piston 2| to the right continues, the pitman rod 28 will move with the piston rod 22, an intermediate position of this travel being shown in Fig. 3.` The stop nut 59 carried by the pitman rod 28 is-eventually moved to the right into engagementwith the stop ring 60, whereupon the actuator 56 is caused to move to the right with the piston 2|, the piston rod 22 and the rod 28.,- As the actuator moves to the right the land 56e moves to the right of the ports 55h of the main valve 56 and hence communication which hasheretofore been possible from the groove 55;* through ports 55h, groove 56) and ports 56h to the right side of the chamber 24 at the right of the partition 56a is cut off and communication is then established from groove 55,1 through ports 55h, groove 56e and ports 55g to the left side of the chamber 24 at the left of the partition 56a. The right side of the chamber then is substantially sealed, but as the pitman rod 28 has some play in the bearing 21 slow seepage of fluid from the right side of chamber 24 will be possible into the left end of the cylinder I1 through the bearing 21. Of course, as the valve actuator'moves to the right its movement is cushioned by the Water within the right hand portion of the chamber 24. Of course, such pressure as the partition 56a of the actuator valve exerts within the right hand portion of the chamber 24 tends to urge the main valve 55 into tight contact with the plug so that no movement of the main valve occurs until such time as the actuator 56 has been moved to the right into engagement with the stop ring 58. At length when the piston 2| moving with the piston rod 22 and actuator 56 has been carried far enough to the right so that the right hand end of the actutor 56 is brought into engagement with the stop ring 58 carried at the right of the main valve 55, the main valve will be carried to the right with the other parts. This movement to the right of the main valve is cushioned by the fluid within the right hand portion of the chamber 24. As the fluid in the right hand portion of the chamber24 can now only escape by seepage through the restricted passage in bearing 21 and as this seepage is quite slow, the movement of the piston to the right toward the end of the right hand stroke is slowed down, thereby slowly bringing the piston to rest atthe end of the stroke to the right. The construction is such that in effect a dashpot is formed through movement of the valve actuator 56 which slows down the movement of the piston 2| near the end of its stroke to the right.

As the main valve 55 slides to the right toward the end of the stroke of the piston 2| toward the right the main valve gradually shifts to the position shown in Fig. 2 with the groove 55j' spanning the space between the fluid intake ports 32a and the second fluid transmission port 32e and with the groove 55e spanning the space between the first fluid transmission port 32h and the exhaust port 32d and with the groove 55g in communication with the exhaust port 32e when the parts are in the position shown `in Fig. 2. Accordingly, fluid will be supplied through the intake ports 32a to the groove 55j and thence through the second fluid transmission port 32c and the second fluid transmission passage formed by the passage 49, the tube 50 and the passage 5| to the right hand end of the cylinder I1, thereby causing the piston 2| to move to the left as is indicated by the arrow adjacent thereto in Fig. 2. As the piston 2| moves to the left the cup 2lb forces out the fluid in the cylinder |1 at the left of the piston causing it to flow through the first fluid transmission passage 48 and first fluid transmission port 32h into the groove 55e and thence through the exhaust port 32d into the fluid exhaust passage 52 to discharge from the exhaust pipe 53. At length when the piston 2| and piston rod 22 have moved to the left sufficiently the plug 30 carried by the piston rod` 22 will contact the rod nut 3| and move the pitman rod 28 with the piston and piston rod to the left until the rod nut 59 contacts the partition 56a of the valve actuator 56, whereupon the actuator will be slid to the left with the moving parts. As the actuator 56 slides to the left and the land 56e moves to the left of the ports 55h communication from groove 55j through ports 55hl and groove 56e and ports 56g to the left side of the chamber 24 at the left of partition 56a is cut off While communication from groove 55f through ports 55h, groove 56f and ports 56h to the right side of the chamber 24 at the right of partition 56a is re-established. The fluid at the left side of the chamber 24 cushions the movement of the Aactuator 56 to the left. At length when the actuator 56 has been slid to the left into contact with the stop ring 56 the main valve 55 will be slid to the left with the piston 2|, piston rod 22, pitman rod 28, and actuator valve 56. As the main valve 56 moves to the left, fluid can only escape from the left side of the chamber 24 through the restricted passage formed around the land 55a by the longitudinal groove 32j and thus movement of the valve 56 to the left is quite slow and, hence, movement of the piston 2| near the end of its stroke to the left is slowed down and cushioned. The fluid at the left portion of chamber 24 gradually and slowly escapes through groove 32f into groove 55e and thence through exhaust port 32d to exhaust passage 52. The construction is such that in eilect a dashpot is formed through movement of the actuator valve 56 so that movement of the piston to the left is slowed down near the end of the stroke to the left. At length when the main valve 55 has been moved into contact with the plug 25, all the parts will be shifted back to the position shown in Fig. 1 and the stroke to the right will commence.

It will be seen that due first to the movement of the retarding valve actuator 56 before the main valve 55 is actuated as the piston 2| approaches the end of its stroke in either direction and then due to the cushioning of the main valve as it moves in either direction and due to the gradual shifting of the delivery of fluid to the opposite side of the piston than the side to which it was first being delivered the change in the direction of the piston at the end of its stroke is very gradually accomplished withoutetrupt stoppage as in the casev f most reciprocating uid motors. Accordingly, the changeover from a stroke in one directionY to a stroke in the opposite direc-tion is made silently and slowly without creating undue wear of the parts and a highly desirable action is accomplished.

The, push key 6I is provided to permit the mainvalve 55 to be slid tothe extreme right hand position in case for any reason the fluid motor should be stopped when the main valve has been shifted to a position half way between itsposition shown in Fig. 1 and Fig. 2. In other words, the push key is provided so that if'the fluid motor is stopped on a dead center position it can be again put into operation. The groove 321' permits shifting of the main valve 55 through activation of the push key 6l.

As the stroke of the piston 2| in the cylinder I1 can be regulated as to length by varying the length of the plug 30 or by varying the length of the nut 3|, and as the speed of reciprocation can be varied bythe regulating valve 5'4 when a `fluid is being supplied under a constant pressure, it is seen that a highly adaptable reciprocatingfluid motor has been provided. While it is particularly contemplated that the motor will be operated by water or other liquid, the mechanism is equally applicable to operation pneumatically by air or other gas. Although the motor is particularly adaptable to use in paper making machinery where electrically operated motors areV undesirable, it is applicable to use in many-'dierent iields.

The device has been found to be successful in actual practice.

It will, ofcourse, be understood that various changes may be made in the form, details, arrangement, and proportions of the various parts without'departure from the scope of the present, invention, which, generally stated, consists in the matter shown, and described, and set forth in the appended claims.

What I claim is:

1. A reciprocating iiuid motor comprising a cylinder, a double acting piston working within said cylinder, means for supplying and exhausting iluid to and from said cylinder at the two sides of said piston, a shiftable main valve controlling ow through said supplying and exhausting means to supply fluid to one side of said piston and exhaust fluid at the other side of said piston when said main valve is shifted to a rst position and to supply iluid to the other side of said piston and exhaust fluid from said one side of the f piston when said main valve is shifted to a second position, a rod having a lost motion connection with said piston to be actuated as the piston approaches the end of its stroke respectively in each direction, a valve actuator having a loose sliding connection with said main valve for actuating said main valve and having a loose sliding connection-with said rod and means cooperating with said valve actuator to form therewith dashpots resisting the shifting movement of said main valve and thereby slowing down the movement of, said piston as it approaches the end of each stroke.

2. A reciprocating fluid motorcomprising a cylinder, a double acting piston working within said cylinder, means 1for supplying and exhausting iluid to and from said cylinder at the two sides of said piston, a shiftable main valve controlling ow-throughsaid supplying andY exhausting means, said main valve when shifted to a side of said piston and exhausted at the other the exhaust of uid side of said piston and when shifted to a second position causing fluid to be supplied at the other side of said piston and exhausted at the :one side of said piston, a valve actuator for actuating said main valve and having a limited movement relative to said main valve before actuating the same, said valve actuator in a rst position relative to said main valve controlling ow of fluid to check and slow down the movement of said main valve from its rst position to its second position and said valve actuator in its second position controlling flow of` iluid toccheck and slow down the movement of said main valve from its second position to its rst position, and a limited play linkage between said piston` and said valve actuator. v

3. A reciprocating fluid motor comprising a cylinder, a double acting piston working within said cylinder, a chambered member, means for supplying uuid under pressure to said chamber, means permitting the exhaust of iiuid from said chamber, rst means affording communication f between said cham-ber and said cylinder at one side of said piston, second means aiTording communication-between said chamber andl said cylinder at the otherside of said piston, a main valve mounted in said chamber and in a rst position establishing communication between said uid supply means and said iirst communication means and between said second communication means and said exhausting means, and in a second position establishing communication between said iiuid supply means and said second 'communication means and between said first coinmunicationv means and said exhausting means, a retarding actuator for said main valve and having a limited movement relative to said main valve to two positions, in one of which said actuator acts in a dual capacity to control the exhaust of fluid from one end of said chamber and check and slow down the movement of saidk main valve as it shifts from its rst position to its second position and to retard the movement of said piston as it approaches one end of its stroke, and in the other of which said actuator acts to control chamber and check and slow down the movement of said main valve as it shifts from `its second position to its 'rst position and to retard the movement of'said pistonas it approaches the other end of its stroke, and a limited play linkage between said piston and said actuator permitting movement of said pistonV through a denite length of stroke in a given direction before said actuator is shifted from its one position to its other position.

4. A reciprocating fluid motor comprising a cylinder, a double acting piston working within the cylinder, acontrol head, a fluid supply conduit running into said head, an exhaust conduit exhausting from said head, rst and second transmission'conduits between said head and said cylinder, the iirst of which transmission conduits communicates with said cylinder at one s ideof said piston and the second of which transmission conduits communicates with said cylinder at the other side of said piston, a main valve mounted in said head and adapted for reciprocating movement' from a first position to a second position and vice versa, said main in relation to said various conduits thatv ink its rst position it will establish communicationbetween saidsupply conduit and said first transfrom the other end of said valve being so constructed mission conduit and between said second transmission conduit and said exhaust conduit and cation between said supply conduit and said second transmission conduit and between said first transmission conduit and said exhaust conduit, a valve actuator mounted in said main valve, a lost motion connection between said main valve and said valve actuator and dashpots controlled by said actuator cushioning the movement of said main valve and slowing the movement of said piston as it approaches each end of its stroke.

5. A reciprocating fluid motor comprising a cylinder, a double acting piston working within the cylinder, a control head, a fluid supply conduit affording communication between a source of fluid supply under pressure and said head, an exhaust conduit exhausting from Vsaid head, first and second transmission conduits between said head and said cylinder, the first transmission conduit affording communication between said head and said cylinder at one side of said piston and the second transmission conduit affording communication between said head and said cylinder at the other side of said piston, a main valve mounted in said head for limited reciprocatlng movement and at one end of its stroke in one direction establishing communication between said supply conduit and said first transmission conduit and between said second transmission conduit and said exhaust conduit, and at the end of its stroke in the opposite direction establishing communication between said supply conduit and said second transmission conduit and between said first transmission conduit and said exhaust conduit, a valve actuator for actuating said main valve and mounted within said main valve for a limited reciprocating movement relative thereto before actuating said main valve, a limited play linkage between said piston and said valve actuator `permitting a definite length of movement of said piston in one direction after said valve actuator and main valve have beer moved to a limit of movement in the opposite direction before the valve actuator is first moved in the direction of movement of the piston by said linkage, and dashpots controlled by said valve actuator resisting movement of said main valve.

6. A reciprocating fluid motor comprising a cylinder, a double acting piston working within said cylinder, a hollow piston rod connected to said piston and projecting beyond said cylinder, a chambered head closing one end of said cylinder, a tail member through which said piston rod works closing the other end of said cylinder, a ported main valve sleeve mounted in the chamber of said head, said sleeve having a central fluid supply port, a pair of fluid exhaust ports spaced from said fluid supply port longitudinally of the sleeve one at either side of said supply port, a first fluid transmission port and a second fluid transmission port,`said first fluid transmission port being longitudinally spaced between said fluid supply port and one of said fluid exhaust ports and the other of said fluid transmission ports being spaced between said fluid supply port and the other of said fluid exhaust ports, a fluid' supply conduit affording communication between a source of fluid supply under pressure and said fluid supply port, a fluid exhaust 'conduit affording communication with said fluid exhaust ports for carrying off the fluid, a first fluid transmission conduit affording communication between said first fluid transmission Y 12 port and said cylinder at one side of said piston, a second Yfluid transmission conduit affording communication between said second fluid transmission port and said cylinder at the other side of said piston, a main valve of tubular formation mounted for reciprocating movement in said sleeve, means limiting the reciprocating movement of said main valve relative to said sleeve in opposite direction, said main valve having a central exterior groove of such width that when said main valve is moved to its limit in one direction said central groove will span said supply port and said first fluid transmission port and when said main valve is moved to its limit in the opposite direction said central groove will span said supply port and said'second fluid transmission port, said main valve having first and second exterior grooves longitudinally spaced from said central groove, the first spaced groove being so formed as to span said second fluid transmission port and one of said fluid exhaust ports when said central groove spans said supply port and said first fluid transmission port and the second spaced groove being so formed as to span said rst fluid transmission port and one of said fluid exhaust ports when said central groove spans said supply port and said second fluid transmission port, an actuator mounted for reciprocation within said main valve. means carried by said main valve limiting the relative reciprocation of said actuator in said main valve inopposite directions, said actuator having tubular recesses at each end thereof and a central cross partition, said actuator having rst and second exterior grooves and the grooved portions of the actuator being respectively ported into the respective recesses of the actuator, said main valve having its central grooved portion ported to admit to one of the grooves of the actuator, the particular groove of the actuator with which the port in the central grooved portion of Athe main valve communicates depending on whether the actuator is reciprocated to its'limit of movement in said main valve in one direction or they opposite direction, a pitman rod slidably received in said head and also slidably received within said hollow piston rod, said pitman rod projecting into the recess at one end of said actuator, inter-engaging stop means carried by one end of said pitman rod and said actuator limiting relative movement between said pitman rod and said actuator in both directions and inter-engaging means carried by the other end of said pitman rod and said piston rod limiting the relative movement of said piston rod relative to said pitman rod in opposite direction, said chamber adjacent its two ends at either side of the cross partition in said actuator having small passages permitting the slow escape of fluid therefrom.

ARTHUR E. BROUGHTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 219,481 Ide Sept. 9, 1879 549,117 Faulkner Nov. 5, 1897 859,961 Meier July 16, 1907 917,917 White Apr. 13, 1909 FOREIGN 'PATENTS Number Country Date 658,030 France Jan. 22, 1929 

